Polishing equipment, and method of manufacturing semiconductor device using the equipment

ABSTRACT

Polishing equipment, comprising a polishing head ( 30 ) having an opened hollow mixing tank ( 32 ) on the opposite side of the side thereof where a polishing pad ( 36 ) is installed, a slurry feed mechanism ( 50 ) for feeding slurry into the mixing tank ( 32 ), an additive liquid feed mechanism ( 60 ) for feeding additive liquid used by adding to the slurry into the mixing tank ( 32 ), and a mixed liquid feed tube ( 34 ) extending from the mixing tank ( 32 ) into the polishing head ( 30 ) and opened to near the rotating center of the polishing pad ( 36 ), wherein the slurry fed by the slurry feed mechanism ( 50 ) and the additive liquid fed by the additive liquid feed mechanism ( 60 ) are fed from the mixed liquid feed tube ( 34 ) to the outside of the polishing pad ( 36 ) in the mixed state in the mixing tank ( 32 ).

This is a continuation of PCT Application No. PCT/JP03/03150 filed Mar.17, 2003, which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to polishing equipment, which isused to planarize an object to be polished such as a silicon wafer, andmore particularly to polishing equipment that polishes a surface of anobject chemically and mechanically with a slurry being supplied onto thesurface. The present invention also relates to a method of manufacturinga semiconductor device, in which this polishing equipment is used forpolishing a surface of a semiconductor wafer.

BACKGROUND OF THE INVENTION

Nowadays, the number of layers that realize multilayered wiring in asemiconductor substrate tends to increase correspondingly to theprogress in the miniaturization and complication of IC structures.Accordingly, the process that planarizes the surface of a substrateafter each succesive thin film is formed thereon has increased inimportance. If the unevenness of the surface after the planarizationprocess, which is performed after the formation of each thin film, isrelatively large because the planarization process lacks precision, thena defect in insulation can occur and cause a short circuit. Also, in theprocess of lithography, the unevenness or irregularity of the surface ofa semiconductor substrate makes the projection on the surface too fuzzyto create microcircuits.

As a prior-art technique for planarizing a semiconductor substrate at ahigh precision, a method of CMP (Chemical Mechanical Polishing) isknown, in which so-called CMP equipment is used. This equipmentgenerally comprises a polishing pad, which is mounted on a polishinghead. In the equipment, the polishing pad is brought into contact with asurface to be polished of a semiconductor substrate while a liquidabrasive containing silica particles is being supplied onto the surface(this abrasive is referred to as “slurry”).

FIG. 3 shows schematically such prior-art CMP equipment as an example.This CMP equipment comprises a surface table 92, which holdssubstantially horizontally a semiconductor substrate 91 as an object tobe polished, and a polishing head 93, which is positioned above thesurface table 92 and has a polishing pad 95 attached on its bottomsurface. For polishing the semiconductor substrate 91, the surface table92, which holds the semiconductor substrate 91, is rotated around itsvertical axis while the is polishing head 93 is also rotated around itsvertical axis. In this condition, the polishing pad 95 is lowered ontothe upper surface of the substrate 91. In design, the diameter of thepolishing pad 95 is smaller than that of the semiconductor substrate 91,so to polish the surface uniformly, the polishing head 93 reciprocates(oscillates) in (horizontal) directions that are parallel to thecontacting surface with the semiconductor substrate 91. During thepolishing, a slurry is sucked from a slurry tank 96 by a pump 97 anddelivered through a slurry supply tube 98 and through a slurry supplytube 94 provided inside the polishing head 93 and supplied onto thepolished surface of the semiconductor substrate 91 externally withrespect to the polishing pad 95.

Furthermore, in another case for polishing a semiconductor substrate 91,an additive liquid (liquid chemical) necessary for achieving a specificpurpose is added to the above mentioned slurry. As such an additive, anadditive liquid that is known to facilitate the planarization of thesurface of the substrate is mixed with the slurry, so that the mixtureis supplied onto the surface being polished of the semiconductorsubstrate 91. In this case, the liquid mixture of the additive liquidand the slurry is prepared in the slurry tank 96 and supplied onto thesurface being polished of the semiconductor substrate 91 in the samemanner as in the above mentioned case where only the slurry is supplied.

By the way, in the above case where the slurry is mixed with an additiveliquid for application, there is a problem that if the additive liquidis mixed with the slurry beforehand, then the effectiveness of theadditive liquid is not demonstrated sufficiently. To solve this problem,it is preferable that the slurry and the additive liquid be mixed justbefore the mixture is supplied onto the surface being polished. However,if the above mentioned conventional polishing equipment is used, thenthere is no way for such mixing, so the slurry and the additive liquidmust be mixed before use with the equipment. In this case, theeffectiveness of the additive liquid is not brought up sufficiently.

SUMMARY OF THE INVENTION

The present invention has been conceived to solve such a problem. It isan object of the present invention to provide polishing equipment thatmixes a slurry and an additive liquid just before this mixture issupplied onto a surface to be polished of a substrate, so that theeffectiveness of the additive liquid is sufficiently brought up toimprove the precision of the polishing.

It is another object of the present invention to provide a method ofmanufacturing a semiconductor device in which the above polishingequipment is used for polishing a surface of a semiconductor wafer.

Polishing equipment according to the present invention comprises asurface table, which holds an object to be polished, and a polishinghead, which has a polishing pad attached on a face that faces a surfaceto be polished of the object held on the surface table. For polishingthe surface of the object, the polishing pad is brought into contactwith the surface of the object. The polishing equipment furthercomprises a slurry feed mechanism, an additive liquid feed mechanism anda mixed liquid feeder. The slurry feed mechanism supplies a slurry tothe polishing head, and the additive liquid feed mechanism supplies alsoto the polishing head an additive liquid, which is added to the slurry.The mixed liquid feeder, which is provided inside the polishing head,mixes the slurry supplied by the slurry feed mechanism and the additiveliquid supplied by the additive liquid feed mechanism and feeds thismixture through an opening provided in the vicinity of the rotationalcenter of the polishing pad to the outside of the polishing pad.

In the polishing equipment according to the present invention, it ispreferable that a stirrer member fixed either on the polishing head oron a polishing head retaining body, which retains the polishing headrotatably, be positioned in the mixed liquid feeder. In this case, it isalso preferable that the stirrer member have a configuration ofprojections or spiral grooves. In addition, it is preferable that astirrer member having a configuration of projections or spiral groovesbe provided on at least part of the inner walls of the mixed liquidfeeder. Furthermore, it is preferable that the surface table hold theobject to be polished in a condition where the surface to be polished ofthe object faces upward and that the polishing pad come from above intocontact with the object.

The present invention also provides a semiconductor device manufacturingmethod, which uses the polishing equipment described above for polishinga surface of a semiconductor wafer (object to be polished). According tothis manufacturing method, semiconductor devices of high precision canbe manufactured at a high throughput and a high yield.

Therefore, high quality semiconductor devices can be manufactured withreduced costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the construction of CMP equipment as anembodiment of polishing equipment according to the present invention.

FIG. 2 is an enlarged sectional partial view of the CMP equipment shownin FIG. 1.

FIG. 3 is a schematic view of prior-art CMP equipment as an example.

FIG. 4 is a flowchart showing an example of semiconductor devicemanufacturing method according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, a preferred embodiment of the present invention is described inreference to the drawings. FIG. 1 is a schematic view of theconstruction of CMP equipment 10 as an embodiment of polishing equipmentaccording to the present invention, and FIG. 2 is an enlarged sectionalview showing a part of the CMP equipment 10. The CMP equipment 10comprises an equipment body that includes a surface table 20, apolishing head 30 and a polishing head retaining body 40, which aremounted on a frame (not shown), and a slurry feed mechanism 50 and anadditive liquid feed mechanism 60, which are detailed later in thissection. The surface table 20 holds substantially horizontally asemiconductor substrate 1 as an object to be polished, and the polishinghead 30 is attached with a polishing pad 36 facing the surface to bepolished (in this case, the upper surface) of the semiconductorsubstrate 1, which is held on the surface table 20. The polishing headretaining body 40 retains the polishing head 30 rotatably around itsvertical axis.

The surface table 20 is mounted on the upper end of a rotating column21, which extends substantially vertically. While the rotating column 21rotates around its axis, the surface table 20 rotates correspondingly ina (substantially horizontal) plane that is perpendicular to the axis. Asuction chuck (not shown) is provided on the upper surface of thesurface table 20, and the suction chuck holds by suction the lowersurface of the semiconductor substrate 1, which is an object to bepolished.

The polishing head 30 comprises a rotating body 31 and a polishing pad36, and the rotating body 31 comprises a trunk portion 31 a and acircular disc portion 31 b, which is positioned below the trunk portion31 a. The polishing pad 36 is attached on the lower face of the circulardisc portion 31 b of the rotating body 31 (in other words, the polishingpad 36 is positioned to face the surface to be polished of thesemiconductor substrate 1, which is held on the surface table 20). Thetrunk portion 31 a of the rotating body 31 is provided with a hollowportion (hereinafter referred to as “mixing tank 32”) that is openupward at the side located opposite to the circular disc portion 31 b(with the polishing pad 36). The lower face of the circular disc portion31 b is planarized at a high degree of precision, so that the polishingpad 36 is attached precisely horizontally. The polishing pad 36 is madeof such a raw material as nonwoven fabric or urethane in a thin circulardisc with a diameter substantially equal to that of the circular discportion 31 b of the rotating body 31. The polishing pad 36 as aconsumable item is attached on the lower face of the circular discportion 31 b by an adhesive, an adhesive bandage or the like, so it canbe removed relatively easily.

The polishing head retaining body 40 is mounted on the frame (not shownas mentioned above) through a plurality of stages, whose movements arecontrolled by a plurality of motors (not shown), so the polishing headretaining body 40 is three dimensionally movable. As shown in FIG. 2,the polishing head retaining body 40 further comprises an extendingportion 41, which extends vertically downward, and a bearing 43, whichis provided around the extending portion 41. The extending portion 41 isplaced from above into and positioned in the above described mixing tank32, which is provided in the rotating body 31 of the polishing head 30,so that the extending portion 41 supports, through the bearing 43, thewhole of the polishing head 30 rotatably around its vertical axis.

The polishing head 30 is provided with a driven gear 37 around thecircular disc portion 31 b of the rotating body 31, and the driven gear37 always meshes with a drive gear 39, which is driven by a motor 38. Asa result, when the motor 38 is activated, the rotational power of themotor is transmitted from the drive gear 39 to the driven gear 37,rotating the whole of the polishing head 30 around its vertical axis.

As shown in FIG. 2, the polishing head retaining body 40 is providedwith a first fluid passage 44 and a second fluid passage 45, whichextend vertically and in parallel with each other inside the extendingportion 41 and open radially outward at outlets provided on the lateralside of the extending portion 41. Furthermore, a retaining body sidestirrer portion 42, which protrudes outward in projections, is providedat the lower periphery of the extending portion 41 while a mixing tankside stirrer portion 33, which protrudes inward in projections in themixing tank 32, is provided on the inside wall of the mixing tank 32.Moreover, a mixed liquid feed passage 34 is provided inside the rotatingbody 31 of the polishing head 30, extending downward from the mixingtank 32, branching and opening at a plurality of positions in thevicinity and the periphery of the rotational center of the polishing pad36.

The slurry feed mechanism 50 comprises a slurry storage tank 51, aslurry supply tube 52 and a first pump 53. The slurry storage tank 51stores a slurry, which is an abrasive liquid that includes ceriaparticles. One end of the slurry supply tube 52 is positioned in theslurry storage tank 51, and the other end of the slurry supply tube 52is threaded into and connected to the upper opening of the first fluidpassage 44, which is provided in the polishing head retaining body 40.The first pump 53 is placed somewhere along the slurry supply tube 52,so that the first pump 53 pumps the slurry from the slurry storage tank51 into the first fluid passage 44. Furthermore, the additive liquidfeed mechanism 60 comprises an additive liquid storage tank 61, anadditive liquid supply tube 62, and a second pump 63. The additiveliquid storage tank 61 stores an additive liquid (liquid chemical),which is used in mixture with the slurry. One end of the additive liquidsupply tube 62 is positioned in the additive liquid storage tank 61, andthe other end of the additive liquid supply tube 62 is threaded into andconnected to the upper opening of the second fluid passage 45, which isprovided in the polishing head retaining body 40. The second pump 63 isplaced somewhere along the additive liquid supply tube 62, so that thesecond pump 63 pumps the additive liquid from the additive liquidstorage tank 61 into the second fluid passage 45. Here, the slurrysupply tube 52 and the additive liquid supply tube 62 are flexible hoses(for example, rubber hoses), whose inner diameter is relatively small,so they can bend and follow the three dimensional movement of thepolishing head retaining body 40.

For planarizing and polishing a semiconductor substrate by the CMPequipment 10, which is constructed as described above, at first, asemiconductor substrate 1 (for example, a silicon wafer) as an object tobe polished is placed and fixed by suction on the surface table 20, withthe surface to be polished of the semiconductor substrate 1 facingupward. In this case, it is preferable that the semiconductor substrate1 be placed and positioned such that the center of the semiconductorsubstrate 1 is at the rotational center of the surface table 20. Afterthe semiconductor substrate 1 is held on the surface table 20, thesurface table 20 with the semiconductor substrate 1 is rotated in ahorizontal plane. Then, the polishing head 30 is rotated around itsvertical axis by the activation of the motor 38 (this action alsoresulting in the rotation of the polishing pad 36 in a horizontalplane), and the polishing head retaining body 40 is lowered to bring thepolishing pad 36 downward and into contact with the surface to bepolished of the semiconductor substrate 1. After the polishing pad 36has come into contact with the surface, starting a polishing process,the polishing head retaining body 40 is moved in a direction that isparallel to the plane where the semiconductor substrate 1 and thepolishing pad 36 are in contact with each other (in this case, in ahorizontal direction) to polish the entire surface.

Just before the polishing of the semiconductor substrate 1 starts, themixture or mixed liquid of the slurry and the additive liquid issupplied onto the surface to be polished of the semiconductor substrate1. This supply of the mixed liquid is executed by the activation of thefirst pump 53, which delivers the slurry from the slurry storage tank 51through the slurry supply tube 52 and through the first fluid passage 44in the polishing head retaining body 40 into the mixing tank 32, and bythe activation of the second pump 63, which delivers the additive liquidfrom the additive liquid storage tank 61 through the additive liquidsupply tube 62 and through the second fluid passage 45 in the polishinghead retaining body 40 into the mixing tank 32. In this way, the slurry,which is supplied by the slurry feed mechanism 50, and the additiveliquid, which is supplied by the additive liquid feed mechanism 60, aremixed in the mixing tank 32, and then the mixed liquid is suppliedthrough the mixed liquid feed passage 34, which is provided in therotating body 41 of the polishing head 40, extending to a plurality ofoutlets in the vicinity and periphery of the rotational center of thepolishing pad 36, to the outside of the polishing pad 36 (in otherwords, the mixed liquid is led onto the lower face of the polishing pad36). By the way, it is necessary that the slurry in the slurry tank 32be always agitated to prevent solid constituents from separating andsettling from liquid constituents.

In this way, while the surface to be polished of the semiconductorsubstrate 1, which is held on the surface table 20, receives the mixedliquid, which is the mixture of the slurry and the additive liquid beingsupplied thereon, the entire surface is polished uniformly because ofthe rotation of the semiconductor substrate 1 itself and the rotationand rocking movements of the polishing head 30 (i.e., the polishing pad36). As a result, the polished surface of the semiconductor substrate 1is planarized up to a high degree of precision. However, if the abovedescribed polishing is continued, then the polishing pad 36 deterioratesgradually, so there are changes (degradations) in the polishing propertyof the equipment. To solve this problem, it is necessary that thepolishing pad be reconditioned (dressed) periodically by a conditioner(not shown).

According to the CMP equipment 10, as mentioned above, the slurry, whichis supplied by the slurry feed mechanism 50, and the additive liquid,which is supplied by the additive liquid feed mechanism 60, are bothsupplied into and mixed in the mixing tank 32, which is a hollow spaceprovided in the polishing head 30, and then the mixed liquid, i.e., themixture of the slurry and the additive liquid, is supplied through themixed liquid feed passage 34, which extends from the mixing tank 32through the polishing head 40 to the outlets provided in the vicinity ofthe rotational center of the polishing pad 36, to the outside (lowerface) of the polishing pad 36. Therefore, the slurry and the additiveliquid are mixed with each other just before they reach the polishedsurface of the semiconductor substrate 1. This mixing timing of the CMPequipment 10 according to the present invention brings the effectivenessof the additive liquid more sufficiently than in a case with prior-artCMP equipment, so an improvement is made in the precision of thepolishing of a semiconductor substrate. Moreover, after the mixedliquid, which is the mixture of the slurry and the additive liquid mixedin the mixing tank 32, comes out of the polishing pad 36, the mixedliquid scatters radially outward by the centrifugal force generated bythe rotation of the polishing head 30. In the CMP equipment 10, becausethe mixed liquid feed passage 34, which is a passageway provided in thepolishing head 30 for the mixed liquid, opens in the vicinity of thecenter of the polishing pad 36, the mixed liquid is spread uniformlyover the entire polished surface of the semiconductor substrate 1.

Furthermore, in the CMP equipment 10, the extending portion 41 of thepolishing head retaining body 40 is positioned in the mixing tank 32 ofthe polishing head 30, and the polishing head 30 rotates around theextending portion 41. While the polishing head 30 is rotating, theextending portion 41 rotates around its axis in the mixing tank 32 as arelative motion. This relative rotation of the extending portion 41agitates effectively and mixes the slurry and the additive liquid in themixing tank 32. Moreover, in the CMP equipment 10, because the retainingbody side stirrer portion 42, which has projections, is provided aroundthe periphery of the extending portion 41 as mentioned above, the slurryand the additive liquid are mixed efficiently and uniformly into themixed liquid. Also, because the mixing tank side stirrer portion 33,which has projections, is provided on the inner wall of the mixing tank32, the mixing of the mixed liquid is more effective. By the way, theretaining body side stirrer portion 42 and the mixing tank side stirrerportion 33 may be provided also in spiral grooves, not only in the formof projections as described above.

The rotation of the extending portion 41 in the mixing tank 32 isachieved as a relative motion because of the rotation of the polishinghead 30, and no other power source is involved. Therefore, this stirringmechanism is simple in construction, which is a merit. It is possible toprovide a construction of independent stirring mechanism that mixes theslurry and the additive liquid in the mixing tank 32, but it willrequire another power source to drive a stirrer member and make theconstruction of the equipment more complicated than the CMP equipment10.

A preferred embodiment of the present invention has been describedabove. However, the scope of the present invention is not limited to theabove description. For example, in the above described embodiment, thesurface table holds the semiconductor substrate in a condition where thesurface to be polished faces upward, and the polishing pad comes fromabove into contact with the surface to be polished (upper surface) ofthe semiconductor substrate. On the contrary, in an alternativeconstruction, the surface table may hold the semiconductor substrate ina condition where the surface to be polished faces downward, and thepolishing pad may come from below into contact with the surface to bepolished (lower surface) of the semiconductor substrate. However, in thelatter construction, the pressure required for delivering the slurry andthe additive liquid through the first and second fluid passages 44 and45 in the polishing head retaining body 40 and through the mixed liquidfeed passage 34 in the polishing head 30 to the outside of the polishingpad 36 must be much higher because the feeding of the slurry and theadditive liquid in this case is against the gravity.

Also, in the above described two embodiments, the polishing head isrotated around its vertical axis in addition to that the surface table,which holds the semiconductor substrate, is rotated. However, forpolishing the surface of the semiconductor substrate, it is necessaryonly that the semiconductor substrate be moved relatively to thepolishing head (polishing pad). Therefore, it is not necessary to rotatethe surface table. Furthermore, the slurry to be used may containalumina, silica and the like in addition to ceria. Moreover, the presentinvention may be applied also to a case where a plurality of additivesare used and mixed with the slurry.

Now, an embodiment of method for manufacturing a semiconductor deviceaccording to the present invention is described. FIG. 4 is a flowchartshowing a process for manufacturing a semiconductor device. After thestart of the semiconductor-manufacturing process, at first, at stepS200, an appropriate process from the following steps S201˜S204 isselected, and the operational flow proceeds to the selected step. Here,step S201 is an oxidization process, which oxidizes a surface of awafer. Step S202 is a CVD process, which forms an insulation film or adielectric film on a surface of a wafer by CVD. Step S203 is anelectrode formation process, which forms electrodes on a wafer by vapordeposition. Step S204 is an ion injection process, which injects ionsinto a wafer.

After the CVD process (S202) or the electrode formation process (S203),the flow proceeds to step S205, which is a CMP process. In the CMPprocess, polishing equipment according to the present invention is usedfor planarization of an interlayer-insulation film or for polish of ametal film or a dielectric film on a semiconductor device, for example,to create damascene.

After the CMP process (S205) or the oxidization process (S201), the flowproceeds to step S206, which is a photolithography process. In thisprocess, the wafer is coated with a resist, the wafer is exposed andprinted with a circuit pattern by an exposure device, and the circuitpattern on the wafer is developed. Then, the next step S207 is anetching process, where the part excluding the resist image, which hasbeen developed, is etched by etching, and then the resist is separatedand removed because it is unnecessary after the etching.

At step S208, a determination is made whether all necessary steps arecompleted or not. If all steps are not yet completed, then the flowreturns to step S200 and repeats the above mentioned steps to create acircuit pattern on the wafer. If the result of the determination at stepS208 is that all necessary steps are completed, then the operationalflow ends.

In the above semiconductor device manufacturing method according to thepresent invention, polishing equipment according to the presentinvention is used in the CMP process, so the throughput of the CMPprocess is improved. An effect of this method is that semiconductordevices are manufactured with costs lower than those in a case wherethey are manufactured by a prior-art semiconductor device manufacturingmethod. Furthermore, polishing equipment according to the presentinvention may be applied to a CMP process of a semiconductor devicemanufacturing method other than that described above. Because asemiconductor device manufacturing method according to the presentinvention achieves a high throughput, the semiconductor devicesmanufactured accordingly are cost-effective.

As described above, polishing equipment according to the presentinvention mixes a slurry and an additive liquid just before they areapplied onto a surface to be polished of a polished object. Therefore,in the polishing equipment, the effectiveness of the additive liquid isdemonstrated more effectively than in prior-art polishing equipment. Asa result, the polished objects achieve an improved degree of precisionin polished condition. Furthermore, the mixed liquid of the slurry andthe additive liquid, after coming out of the polishing pad, scattersradially outward by the centrifugal force generated by the rotation ofthe polishing head. In the polishing equipment according to the presentinvention, because the mixed liquid feed passage, which is a passagewayprovided in the polishing head for the mixed liquid, opens in thevicinity of the center of the polishing pad, the mixed liquid is spreaduniformly over the entire polished surface of the polished object.

Also, by a semiconductor device manufacturing method that uses thepolishing equipment in a process that polishes a surface of asemiconductor wafer, semiconductor devices of high precision can bemanufactured at a high throughput and a high yield. As a result, highquality semiconductor devices can be manufactured with reduced costs,and these high quality semiconductor devices can be distributed atrelatively low prices.

1. Polishing equipment comprising a surface table, which holds an objectto be polished, and a polishing head, which has a polishing pad attachedon a face thereof that faces a surface to be polished of said objectheld on said surface table, wherein said polishing pad is brought intocontact with said surface of said object to polish said surface; saidpolishing equipment further comprising: a slurry feed mechanism, whichsupplies a slurry to said polishing head; an additive liquid feedmechanism, which supplies also to said polishing head an additive liquidto be added to said slurry; and a mixed liquid feeder, which is providedinside said polishing head and mixes said slurry supplied by said slurryfeed mechanism and said additive liquid supplied by said additive liquidfeed mechanism and feeds this mixture through an opening provided in avicinity of a rotational center of said polishing pad to an outside ofsaid polishing pad.
 2. The polishing equipment set forth in claim 1,wherein: said polishing head is retained rotatably by a polishing headretaining body; and a stirrer member, which is provided either on saidpolishing head or on said polishing head retaining body, is positionedin said mixed liquid feeder.
 3. The polishing equipment set forth inclaim 2, wherein said stirrer member has a configuration of projectionsor spiral grooves.
 4. The polishing equipment set forth in claim 1,wherein: said polishing head is retained rotatably by a polishing headretaining body; said mixed liquid feeder occupies a space between saidpolishing head and said polishing head retaining body; and a stirrermember having a configuration of projections or spiral grooves isprovided on at least part of inner walls of said polishing head and saidpolishing head retaining body, which define said space.
 5. The polishingequipment set forth in claim 1, wherein: said surface table holds saidobject to be polished such that said surface to be polished facesupward; and said polishing pad comes from above into contact with saidobject.
 6. The polishing equipment set forth in any of claims 1˜5,wherein said object to be polished is a semiconductor wafer.
 7. Asemiconductor device manufacturing method comprising a step where thepolishing equipment set forth in claim 6 is used to polish a surface ofa semiconductor wafer.